The Details: The Ica Desert of Peru was once the thriving seafloor of an ancient ocean. Today, it’s one of the driest places on the planet and among the best fossil-hunting grounds ever found. Gregory Dicum, a travel writer from San Francisco, hiked for two days with a local guide to discover preserved giant shark teeth, fields littered with fossils, and seashells from creatures long extinct. At one place, standing in a remote desert gully, Dicum and his guide walked up on a pod of fossilized whales—skulls, fins, ribs, vertebrae, baleen, and skin preserved through the eons under shifting Peruvian sands.